About the Cover

June 10, 2009; Volume 29,Issue 23

Cover image

Cover legend: The python and other henophidian snakes have retinas containing rod and cones that express the Rh1 rod opsin and the SWS1 and LWS cone opsin. This pattern of visual pigment expression in “lower” snakes has implications for understanding the evolution of photopigments in tetrapods. For more information, see the article by Davies et al. in this issue (pages 7519–525).